The good news: centrifugal pumps tend to have no break-away torque, and torque goes up with speed. This is a desirable characteristic.

There are many types of positive displacement pumps that can be the opposite, and can be “sticky”. You need to know all of this to make sure drive equipment is properly selected. With some knowledge of pump curves and hydraulics, it’s even possible to calculate (estimate) meaningful process variables from information harvested from an AC drive. You can create a model in a PLC to calculate flow rate and pressure from speed and power factor corrected power, if a mechanical engineer can furnish a pump curve and a system curve. There are a lot of things like this that are unique to pumps (and compressors) that are things that typical electrical engineers don’t know.